The Credit Based Shaper (CBS) queueing discipline allows bandwidth
reservation with sub-milisecond precision. It is defined by the
802.1Q-2014 specification (section 8.6.8.2 and Annex L).
The syntax is:
tc qdisc add dev DEV parent NODE cbs locredit <LOCREDIT>
hicredit <HICREDIT> sendslope <SENDSLOPE>
idleslope <IDLESLOPE>
(The order is not important)
Signed-off-by: Vinicius Costa Gomes <vinicius.go...@intel.com>
---
tc/Makefile | 1 +
tc/q_cbs.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 135 insertions(+)
create mode 100644 tc/q_cbs.c
diff --git a/tc/Makefile b/tc/Makefile
index 777de5e6..24bd3e2e 100644
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -69,6 +69,7 @@ TCMODULES += q_hhf.o
TCMODULES += q_clsact.o
TCMODULES += e_bpf.o
TCMODULES += f_matchall.o
+TCMODULES += q_cbs.o
TCSO :=
ifeq ($(TC_CONFIG_ATM),y)
diff --git a/tc/q_cbs.c b/tc/q_cbs.c
new file mode 100644
index 00000000..80dd599a
--- /dev/null
+++ b/tc/q_cbs.c
@@ -0,0 +1,134 @@
+/*
+ * q_cbs.c CBS.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Authors: Vinicius Costa Gomes <vinicius.go...@intel.com>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+static void explain(void)
+{
+ fprintf(stderr, "Usage: ... cbs hicredit BYTES locredit BYTES sendslope
BPS idleslope BPS\n");
+}
+
+static void explain1(const char *arg, const char *val)
+{
+ fprintf(stderr, "cbs: illegal value for \"%s\": \"%s\"\n", arg, val);
+}
+
+static int cbs_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct
nlmsghdr *n)
+{
+ int ok = 0;
+ struct tc_cbs_qopt opt = {};
+ struct rtattr *tail;
+
+ while (argc > 0) {
+ if (matches(*argv, "hicredit") == 0) {
+ NEXT_ARG();
+ if (opt.hicredit) {
+ fprintf(stderr, "cbs: duplicate \"hicredit\"
specification\n");
+ return -1;
+ }
+ if (get_s32(&opt.hicredit, *argv, 0)) {
+ explain1("hicredit", *argv);
+ return -1;
+ }
+ ok++;
+ } else if (matches(*argv, "locredit") == 0) {
+ NEXT_ARG();
+ if (opt.locredit) {
+ fprintf(stderr, "cbs: duplicate \"locredit\"
specification\n");
+ return -1;
+ }
+ if (get_s32(&opt.locredit, *argv, 0)) {
+ explain1("locredit", *argv);
+ return -1;
+ }
+ ok++;
+ } else if (matches(*argv, "sendslope") == 0) {
+ NEXT_ARG();
+ if (opt.sendslope) {
+ fprintf(stderr, "cbs: duplicate \"sendslope\"
specification\n");
+ return -1;
+ }
+ if (get_s32(&opt.sendslope, *argv, 0)) {
+ explain1("sendslope", *argv);
+ return -1;
+ }
+ ok++;
+ } else if (matches(*argv, "idleslope") == 0) {
+ NEXT_ARG();
+ if (opt.idleslope) {
+ fprintf(stderr, "cbs: duplicate \"idleslope\"
specification\n");
+ return -1;
+ }
+ if (get_s32(&opt.idleslope, *argv, 0)) {
+ explain1("idleslope", *argv);
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "help") == 0) {
+ explain();
+ return -1;
+ } else {
+ fprintf(stderr, "cbs: unknown parameter \"%s\"\n",
*argv);
+ explain();
+ return -1;
+ }
+ argc--; argv++;
+ }
+
+ tail = NLMSG_TAIL(n);
+ addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
+ addattr_l(n, 2024, TCA_CBS_PARMS, &opt, sizeof(opt));
+ tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
+ return 0;
+}
+
+static int cbs_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+ struct rtattr *tb[TCA_CBS_MAX+1];
+ struct tc_cbs_qopt *qopt;
+
+ if (opt == NULL)
+ return 0;
+
+ parse_rtattr_nested(tb, TCA_CBS_MAX, opt);
+
+ if (tb[TCA_CBS_PARMS] == NULL)
+ return -1;
+
+ qopt = RTA_DATA(tb[TCA_CBS_PARMS]);
+ if (RTA_PAYLOAD(tb[TCA_CBS_PARMS]) < sizeof(*qopt))
+ return -1;
+
+ fprintf(f, "hicredit %d ", qopt->hicredit);
+ fprintf(f, "locredit %d ", qopt->locredit);
+ fprintf(f, "sendslope %d ", qopt->sendslope);
+ fprintf(f, "idleslope %d ", qopt->idleslope);
+
+ return 0;
+}
+
+struct qdisc_util cbs_qdisc_util = {
+ .id = "cbs",
+ .parse_qopt = cbs_parse_opt,
+ .print_qopt = cbs_print_opt,
+};
--
2.14.2
